A slit lamp microscope is used, by an ophthalmologist, for observing an eye of an examinee.
A conventional slit lamp microscope will be explained.
The slit lamp microscope irradiates an eye of an examinee with a slit-light from an oblique direction so as to visualize and observe transparent or semi-transparent tissues. The slit lamp microscope includes a slit-light optical system for emitting the slit-light and a microscope unit.
In case of irradiating the eye of the examinee with the slit-light only, an irradiation point on the eye is sometimes unknown. In this state, if a picture of the eye is taken, the slit-light will be focused on a slit. To solve this problem, a backlight source for illuminating a circumference of the slit-light, is provided to the conventional slit lamp microscope.
Japanese Laid-open Patent Publication No. 2011-177273 discloses a light emitting diode (LED) used for emitting a backlight. An auxiliary lamp unit including the LED is attached to a front end of a flexible arm.
The flexible arm is attached to a face supporting section, which supports a face of the examinee, and the backlight is emitted from a position above the eye of the examinee.
In the slit lamp microscope disclosed in Japanese Laid-open Patent Publication No. 2011-177273, the slit-light optical system for emitting the slit-light and the auxiliary lamp unit for emitting the backlight are separately provided.
However, in the conventional slit lamp microscope, irradiation points of the slit-light and the backlight on the eye of the examinee are separately adjusted when the slit-light and the backlight are emitted. So it takes a long time to adjust the both irradiation points.